#49: implement semantic highlighting

Works for all symbols and keywords. Namespaces are treated as separate highlighted elements. For symbols that was the behaviour by default and for keywords the ns range had to be manually added.

src/main/kotlin/com/github/brcosta/cljstuffplugin/extensions/ClojureAnnotator.kt

@@ -67,10 +67,6 @@ class ClojureAnnotator : Annotator {
         }
     }
 
-    private fun isNamespaced(element: ClKeyword) =
-        (element.text?.contains("/") == true) &&
-                (element.parentOfType<ClSexpComment>(false) == null)
-
     private fun isNsReaderMacro(element: PsiElement) =
         (element.prevSibling != null) &&
                 (element.prevSibling.text == "#:") &&
@@ -81,4 +77,11 @@ class ClojureAnnotator : Annotator {
                 (element.nextSibling is LeafPsiElement) &&
                 ((element.nextSibling as LeafPsiElement).elementType.debugName == "ns separator") &&
                 (element.parentOfType<ClSexpComment>(false) == null)
+
+    companion object {
+        fun isNamespaced(element: ClKeyword) =
+            (element.text?.contains("/") == true) &&
+                    (element.parentOfType<ClSexpComment>(false) == null)
+    }
+
 }

src/main/kotlin/com/github/brcosta/cljstuffplugin/extensions/ClojureColorsAndFontPageEx.kt

@@ -1,17 +1,20 @@
 package com.github.brcosta.cljstuffplugin.extensions
 
+import com.intellij.codeHighlighting.RainbowHighlighter
+import com.intellij.lang.Language
 import com.intellij.openapi.editor.colors.TextAttributesKey
 import com.intellij.openapi.fileTypes.SyntaxHighlighter
 import com.intellij.openapi.options.colors.AttributesDescriptor
 import com.intellij.openapi.options.colors.ColorDescriptor
-import com.intellij.openapi.options.colors.ColorSettingsPage
+import com.intellij.openapi.options.colors.RainbowColorSettingsPage
 import cursive.ClojureIcons
+import cursive.ClojureLanguage
 import cursive.highlighter.ClojureSyntaxHighlighter
 import org.jetbrains.annotations.NonNls
 import javax.swing.Icon
 
 @Suppress("unused")
-class ClojureColorsAndFontsPageEx : ColorSettingsPage {
+class ClojureColorsAndFontsPageEx : RainbowColorSettingsPage {
 
     override fun getDisplayName(): String {
         return "Clojure Extras"
@@ -38,18 +41,28 @@ class ClojureColorsAndFontsPageEx : ColorSettingsPage {
     }
 
     override fun getAdditionalHighlightingTagToDescriptorMap(): Map<String, TextAttributesKey> {
-        val map: MutableMap<String, TextAttributesKey> = mutableMapOf()
+        val map = RainbowHighlighter.createRainbowHLM()
         map["keyword-namespace"] = KEYWORD_NAMESPACE
         map["symbol-namespace"] = SYMBOL_NAMESPACE
         map["head-symbol-namespace"] = HEAD_SYMBOL_NAMESPACE
         return map
     }
 
+    override fun isRainbowType(type: TextAttributesKey?): Boolean {
+        return type == SEMANTIC_HIGHLIGHTING
+    }
+
+    override fun getLanguage(): Language? {
+        return ClojureLanguage.getInstance()
+    }
+
     companion object {
         private val ATTRS: Array<AttributesDescriptor>
         val KEYWORD_NAMESPACE = TextAttributesKey.createTextAttributesKey("Keyword Namespace")
         val SYMBOL_NAMESPACE = TextAttributesKey.createTextAttributesKey("Symbol Namespace")
         val HEAD_SYMBOL_NAMESPACE = TextAttributesKey.createTextAttributesKey("Head Symbol Namespace")
+        val SEMANTIC_HIGHLIGHTING = TextAttributesKey.createTextAttributesKey("Semantic Highlighting")
+
         init {
             ATTRS = arrayOf(
                 AttributesDescriptor("Keyword Namespace", KEYWORD_NAMESPACE),

src/main/kotlin/com/github/brcosta/cljstuffplugin/extensions/codeInsight/daemon/ClojureRainbowVisitor.kt

@@ -0,0 +1,76 @@
+package com.github.brcosta.cljstuffplugin.extensions.codeInsight.daemon
+
+import com.github.brcosta.cljstuffplugin.extensions.ClojureAnnotator.Companion.isNamespaced
+import com.github.brcosta.cljstuffplugin.extensions.ClojureColorsAndFontsPageEx.Companion.SEMANTIC_HIGHLIGHTING
+import com.intellij.codeInsight.daemon.RainbowVisitor
+import com.intellij.codeInsight.daemon.UsedColors
+import com.intellij.codeInsight.daemon.impl.HighlightInfo
+import com.intellij.codeInsight.daemon.impl.HighlightVisitor
+import com.intellij.openapi.util.UserDataHolderEx
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiFile
+import cursive.psi.api.ClKeyword
+import cursive.psi.api.ClojureFile
+import cursive.psi.api.symbols.ClSymbol
+
+/**
+ * Enables semantic highlighting for all symbols and keywords. Namespaces are treated as separate highlighted elements.
+ */
+class ClojureRainbowVisitor : RainbowVisitor() {
+    override fun suitableForFile(file: PsiFile): Boolean {
+        return file is ClojureFile
+    }
+
+    override fun visit(element: PsiElement) {
+        val maybeName = when (element) {
+            is ClSymbol -> element.name
+            is ClKeyword -> element.name
+            else -> null
+        }
+        maybeName?.let { elementName ->
+            element.context?.let { context ->
+                fun separateNsHighlighting(keyword: ClKeyword): List<HighlightInfo> {
+                    fun rangedInfo(name: String, start: Int, end: Int): HighlightInfo {
+                        val color =
+                            UsedColors.getOrAddColorIndex((context as UserDataHolderEx), name, highlighter.colorsCount)
+                        return highlighter.getInfo(color, start, end, SEMANTIC_HIGHLIGHTING)
+                    }
+
+                    val start = keyword.textRange.startOffset
+                    val nsEnd = start + keyword.text.indexOf('/')
+                    return listOf(
+                        rangedInfo(
+                            keyword.namespace,
+                            start,
+                            nsEnd,
+                        ),
+                        rangedInfo(
+                            elementName,
+                            nsEnd,
+                            keyword.textRange.endOffset,
+                        )
+                    )
+                }
+
+                if (element is ClKeyword && isNamespaced(element))
+                    separateNsHighlighting(element).forEach(::addInfo)
+                else
+                    // separate ns highlighting for symbols works by default
+                    addInfo(
+                        getInfo(
+                            context,
+                            element,
+                            elementName,
+                            SEMANTIC_HIGHLIGHTING
+                        )
+                    )
+
+            }
+        }
+    }
+
+    override fun clone(): HighlightVisitor {
+        return ClojureRainbowVisitor()
+    }
+
+}

src/main/resources/META-INF/plugin.xml

@@ -20,6 +20,7 @@
         <externalAnnotator language="Clojure" implementationClass="com.github.brcosta.cljstuffplugin.extensions.CljKondoAnnotator" />
 
         <colorSettingsPage implementation="com.github.brcosta.cljstuffplugin.extensions.ClojureColorsAndFontsPageEx"/>
+        <highlightVisitor implementation="com.github.brcosta.cljstuffplugin.extensions.codeInsight.daemon.ClojureRainbowVisitor"/>
 
         <additionalTextAttributes file="colors/ClojureStuffDefaultColors.xml" scheme="Default"/>
         <additionalTextAttributes file="colors/ClojureStuffDarculaColors.xml" scheme="Darcula"/>